VirtualBox will not start with > 3.5GB of Ram

[Amar]

Hi all,

I have installed Ubuntu 9.04 Jaunty Jackalope as a host OS and then installed VirtualBox 3.0.2. The machine is a HP DL380 G4 with Dual Xeon 3.4GHz (which is a non-VT CPU) and 12GB of ram.

I created my first VM and installed SLES10 SP2 on it. I had to disable Hardware Virtualization by modifying the XML file, because it was checked and grayed out. The VM wouldn't start with 4GB of memory allocated to it. The error message I got when starting with VT-x enabled and 4GB of memory was: "VERR_VMX_NO_VMX". So the situation now is: VT-x disabled, 4GB of memory, 1CPU core (more is not possible to select), 50GB dynamically expanding HD.
Then I wanted to install IBM WebSphere Portal Server, when I ran the installer it was extremely slow. After one hour I got through the installation screens (which I did on a console because the GUI wouldn't load after 15 minutes), the installation started. Next morning I came back and it was not even on 25%!

I wanted to see whether this would be faster on another machine, so I got my MacBook (2.4ghz C2D, 4gb ram) and did EXACTLY the same installation of SLES10 SP2 and Portal Server (however with 2gb allocated to the guest). This went blazingly fast. I thought there must be something wrong here, a simple notebook cannot be faster than a dual xeon server with 12gb of memory!

After that I tried something that works but I cannot understand:
Enabled VT-x again in the XML file, and allocated 3584mb (3,5GB) of memory to the guest. It started and it looks like it's going a lot faster now. I got through the installation steps a lot faster, the actual installation has just started. It also remains responsive during installation, something that was not the case earlier.


My question:
Why does the guest start if 3.5GB of ram is allocated? When I allocate 3585MB instead of 3584MB it gives me the "VERR_VMX_NO_VMX" error again.

The CPU has been checked with the Intel utility (http://downloadcenter.intel.com/Detail_ ... &;lang=eng) and there is also no bios option to enable VT, so I would think that hardware virtualization is at all not possible. How come it does start with 3.5GB though? The bios version of the HP is P51.


I don't want to use my macbook as a server, what am I missing here?


Any help is appreciated.

Thanks.

[baf]

Is it the 32 or 64 bit version of ubuntu?

[Amar]

Just when I thought I had given all possible information..

It's the 64 bit version.

The SLES guest is 32 bit bigsmp kernel. I have tried downloading OpenSuSE 11.1 64 bit, but when I boot up the VM it immediately comes up with the error message. It doesn't go to load the DVD iso.

[Amar]

I just checked with the new installation with 3.5gb ram and VT-x on, but it is again stuck around 25%. Seems like the menu's were going a lot faster but the installation itself is still not going well.

There shouldn't be a problem with the installation files, as they have been used before. It's a zip package, not a DVD.

[Sasquatch]

32 bit Guests are limited to 3,5 GB of RAM. This is done, because normal 32 bit OSs can't handle more than that. So what if your Linux Guest uses the bigmem kernel so it can address 6 GB, it won't change things in VB. You need to use a 64 bit Guest in order to select more than 3,5 GB of RAM, but you need the appropriate hardware too (check the manual for that).